Electric heater assembly



June 29, 1965 R. L. POST ETAL 3,192,361

ELECTRIC HEATER ASSEMBLY 2 Sheets-Sheet 1 Filed Aug. 8, 1962 v T WLMM AO D; w

RT am 2 Sheets-Sheet 2 wi TuomAs AOQAVETZ ATTORNE/S June 29, 1965 FiledAug. 8, 1962 VIIQAZ R z \W United States Patent 3,192,361 ELECTRICHEATER ASSEMBLY Richard L. Post, Glenshaw, and Thomas A. Oravetz,

Level Green, Pa., assignors to Edwin L..Wiegand Company, Pittsburgh, Pa.

Filed Aug. 8, 1962, Ser. No. 215,645 8 Claims. (Cl. 219-458) The presentinvention relates to electric heater assemblies, more particularly toassemblies adapted for use in ranges, hot plates and the like, an dtheprinci al object of the invention is to provide new and improvedassemblies of the character described.

Although many prior-art heater assemblies of the surface, or range unit,type utilizing a tubular sheathed electric resistance heating elementhave been satisfactory in most respects, a common disability has beenthe high cost of the assembly which limited its use inlow pricestructures. One of the. primary objects of the present invention,therefore, is. the provision of an assembly incorporating a tubularsheathed electric resistance heating element which can be manufacturedand sold at a sufficiently low price to justify its use in even lowprice structures; This and other advantages will readily become apparentfrom a study of the following description and from the drawings appendedhereto.

In the drawings accompanying this specification and forming a part ofthis application there is shown, for purpose of illustration, anembodiment which the invention may assume, and in these drawings:

FIGURE 1 is a top plan view of an electric heater assembly embodying thepresent invention,

FIGURE 2 is a sectional view generally corresponding to the line 2-2 ofFIGUREv 1',

FIGURE 3 is an exploded perspective view of certain details, and

FIGURE 4 is an enlarged, broken sectional view taken through the detailsseen in FIGURE 3 and generally corresponding to the line 4-4 but showingthe details in assembled relation.

With reference to FIGURES 1 and 2, the present heater assembly utilizesthe usual elongated, tubular sheathed electric resistance heatingelement whose intermediate, heat-generating portion 11 provides aplurality of convolutions forming a generally flat, centrally apertured,circular heating surface which is adapted to underlie and support avessel (not shown) to be heated. Such convolutions are preferablyflattened at the top (see FIGURE 2) to improve heat-contact with thebottom of the vessel to be heated. The terminal ends 12 of the heatingelement are disposed in side-by-side relation beneath the heatingsurface of the intermediate, heat-generating element portion 11 andextend beyond such heating surface for connection to a source ofelectrical energy.

Electrically connected to the free ends of respective element terminalends 12 are insulated, flexible lead wires 13. Protecting each of theconnections aforesaid is a molded body 14 of heat-resistant rubber orthe like which extends between and is bonded to a respective elementterminal end and the insulated covering of its attached lead wire. Thisconstruction completely seals the interior of the element againstmoisture or other foreign material, adequately protects the electricalconnections against grounds or shorts, and eliminates the usualexpensive terminal block.

In common with prior-art, range-type or surface heater assemblies, theassembly herein disclosed is adapted to be supported by an .aperturedpanel 15 which, in the present embodiment, may be considered as the toppanel of a range or as the corresponding part of a hot plate or thelike. As herein disclosed, a ring-like member 3,192,361 Patented June29, 1965 16 having an upper, radially outwardly extending flange portion17, a lower, radially inwardly extending flange portion 18, and anintermediate, tubular portion 19, is supported by the panel 15 with thetubular portion 19 disposed within the panel aperture and with theflange portion 17 resting upon the upper surface of the panel. Supportedby the member 16 is the usual removable reflector, or drip pan, 20having a radially outwardly extending flange 21 which rests upon theflange 18 of the member 16. Pan 20 is notched out at 22 to pass theelement terminal ends 12.

Turning now to the means for supporting the element 10 Within the ringmember 16, a supporting member 23, frequently known as a spider,underlies the heatgenerating portion of the element and rests upon thepan flange 21. Spider 23 provides three structurally integrated legs 24,25 and 26 (see FIGURE 1) arranged in spoke-like relation beneath theheat-generating portion of the element. The spider legs are herein shownformed of heat-resistant strip material, such as metal, positioned onedge for maximum strength in a vertical direction with the outermost legends resting upon the pan flange 21 and abutting the tubular ringportion 19.

As best seen in FIGURE 3, spider 23 is formed of two sheet metal pieceseach having rectilinear portions 27 and 28 in angular relation joined byan arcuate portion 29. Rectilinear portions 27 are adapted to bedisposed in face-to-face relation as shown and may be structurallyintegrally united by means of rivets 30. Port-ions 27, of course,combine to form the spider leg 24 while portions 28 form respectivespider legs 25, 26. Arcuate spider portions 29 together formapproximately a half circle which is generally concentric with thecentral aperture of the element heating surface when the element and thespider are in superposed relation.

In the present embodiment, the heating element 10 and the spider 23 areadapted to be secured together and for this purpose, any convenientmeans may be employed. At the present time and as best seen in FIGURE 2,metal loops 31 are welded to the underside of certain elementconvolutions to closely receive the spider leg 24. For preventingunintentional disassembly of the spider and the element, the spider leg24 is notched at 32 (see also FIGURE 3) to provide shoulders betweenwhich the loops are confined.

While the structure thus far described provides a complete, workableassembly, it is common practise to position a medallion 33 or like bodywithin the central aperture of the element heating surface in order toimpart a more finished appearance to the assembly. As best seen inFIGURES 3 and 4, medallion 33 preferably comprises a shallow, invertedsheet-metal cup whose annular wall 34 is of stepped diameter to providean upwardly facing annular shoulder 35.

For securing the medallion to the spider, the arcuate portions 29 of thelatter are lanced out at 36 to provide circumferentially spaced-aparttongues 37. With particular reference to FIGURE 4, the lower portion ofeach tongue 37 provides a radially inwardly projecting ledge upon whichthe lower margin of the medallion wall 34 rests while the upper portionof each tongue is spaced radially inwardly of its arcuate spider portionto closely receive the medallion wall. With the medallion thuspositioned, each tongue 37 may be forced radially outwardly to grippingrelation with the medallion to thus retain it assembled with the spider.

Since the spider tongues 37 are rather widely spaced, there might betendency for the medallion to rock and eventually work itself loose. Toprevent this, the arcuate portion 29 of each spider part is providedwith radial inward projections 38 intermediate the spider tongues.

As seen in FIGURE 4, such projections may conveniently be formed bypunching small portions of the spider radially inwardly an amount onlysufficient to form projecbions but not sutlicient to punch the portionscompletely out.

Still referring to FIGURE 4, the lowermost projections 38 are positionedto engage beneath the lower edge of the medallion wall 34 while theuppermost projections 38 engage the upwardly facing, medallion wallshoulder 35 thus effectively preventing tilting of the medallion aboutthe mounting tongues 37.

While a shallow, inverted cup-shaped medallion has been shown anddescribed, it is to be understood that the invention contemplates theuse of medallions of different shapes or the use of thermal sensingunits or the like in place of medallions.

In view of the foregoing, it will be apparent to those skilled in theart that we have accomplished at least the principal object of ourinvention and it will also be apparent to those skilled in the art thatthe embodiment herein described may be variously changed and modified,without departing from the spirit of the invention, and that theinvention is capable of uses and has advantages not herein specificallydescribed; hence it will be appreciated that the herein disclosedembodiment is illustrative only, and that our invention is not limitedthereto.

We claim:

1. A heater assembly comprising a sheathed electric resistance heatingelement having a heat-generating portion providing an apertured,generally plane heating surface for underlying and supporting a vesselto be heated, a support member underlying and supporting theheatgenerating portion of said element and partially margining theelement heating surface aperture, means carried by that part of saidsupport member which margins said element heating surface aperture andcomprising a generally vertically disposed tongue having a lower portionaffixed to said support member margining part and an upper, free endportion spaced radially inwardly of said support member margining part,and a body aligned with the element heating surface aperture and havinga portion initerposed between said support member margining part and thefree end portion of said tongue.

2. The construction of claim 1 wherein said body portion rests upon thelower portion of said tongue adjacent its juncture with said supportmember margining part.

3. The construction of claim 1 wherein said body portion is grippedbetween said support member margining part and the free end portion ofsaid tongue.

4. The construction of claim 1 wherein said support member marginingpart provides a pair of radially inwardly extending projections whichrespectively engage upper and lower body portions to prevent tilting ofsaid body relative to said support member.

5. The construction of claim 4 wherein said body portion is a sheetmetal annulus, wherein the sheet metal annular body portion provides anupwardly facing annular flange, and wherein one of said projectionsengages the lower edge of said body portion and the other engages saidannular flange.

6. The construction of claim 1 wherein said tongue is integral with saidsupport member margining part and is formed by lancing said tonguetherefrom.

7. The construction of claim 6 wherein said-support member provides apair of circumferentially spaced tongues in generally opposed relationwith each other.

8. The construction of claim 7 wherein said body portion is a sheetmetal annulus, wherein said support member margining part provides apair of radially inwardly extending projections intermediate saidtongues, and wherein said projections respectively engage upper andlower body annular portions to prevent tilting of said body relative tosaid support member.

RICHARD M. WOOD, Primary Examiner.

1. A HEATER ASSEMBLY COMPRISING A SHEATHED ELECTRIC RESISTANCE HEATINGELEMENT HAVING A HEAT-GENERATING PORTION PROVIDING AN APERTURED,GENERALLY PLANE HEATING SURFACE FOR UNDERLYING AND SUPPORTING A VESSELTO BE HEATED, A SUPPORT MEMBER UNDERLYING AND SUPPORTING THEHEATGENERATING PORTION OF SAID ELEMENT AND PARTIALLY MARGINING THEELEMENT HEATING SURFACE APERTURE, MEANS CARRIED BY THAT PART OF SAIDSUPPORT MEMBER WHICH MARGINS SAID ELEMENT HEATING SURFACE APERTURE ANDCOMPRISING A GENERALLY VERTICALY DISPOSED TONGUE HAVING A LOWER PORTIONAFFIXED TO SAID SUPPORT MEMBER MARGINING PART AND AN UPPER, FREE ENDPORTION SPACED RADIALLY OF SAID SUPPORT MEMBER MARGINING PART, AND ABODY ALIGNED WITH THE ELEMENT HEATING SURFACE APERTURE AND HAVING APORTION INTERPOSED BETWEEN SAID SUPPORT MEMBER MARGINING PART AND THEFREE END PORTION OF SAID TONGUE.